Category: fault model
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Modelling time to next reported fault
After the arrival of a fault report for a program, what is the expected elapsed time until the next fault report arrives (assuming that the report relates to a coding mistake and is not a request for enhancement or something the user did wrong, and the number of active users remains the same and the…
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Lifetime of coding mistakes in the Linux kernel
What is the lifetime of coding mistakes in the Linux kernel? Some coding mistakes result in fault reports (some of which are fixed), while many are removed when the source that contains them is deleted/changed during ongoing development. After fixing the coding mistake(s) in the kernel that generated a reported fault, developer(s) log the commit…
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Deep dive looking for good enough reliability models
A previous post summarised the main highlights of my trawl through the software reliability research papers/reports/data, which failed to find any good enough models for estimating the reliability of a software system. This post summarises a deep dive into the technical aspects of the research papers. I am now a lot more confident that better…
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Example of an initial analysis of some new NASA data
For the last 20 years, the bug report databases of Open source projects have been almost the exclusive supplier of fault reports to the research community. Which, if any, of the research results are applicable to commercial projects (given the volunteer nature of most Open source projects and that anybody can submit a report)? The…
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Extracting information from duplicate fault reports
Duplicate fault reports (that is, reports whose cause is the same underlying coding mistake) are an underused source of information. I sometimes email the authors of a paper analysing fault data asking for information about duplicates. Duplicate information is rarely available, because the authors don’t bother to record it. If a program’s coding mistakes are…
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Good enough reliability models: still an unknown
Estimating the likelihood that a software system will operate as intended, for some period of time, is one of the big problems within the field of software reliability research. When software does not operate as intended, a fault, or bug, or hallucination is said to have occurred. Three events need to occur for a user…